Monday, October 28, 2013

Geologists say that the volume of molten magma underneath Yellowstone is somewhere between 50 to 145 cubic miles. But earthquakes are a bigger threat.

People in Wyoming sometimes speculate about The Big One, the day when Yellowstone's magma chamber blows its top, causing a cataclysmic eruption such as the one 640,000 years ago that wiped from the map woolly mammoths, giant ground sloths and prehistoric Democrats.

As it turns out, we have more to fear from earthquakes (and possibly Liz Cheney) than The Big One. Swarms of earthquakes regularly rattle the Yellowstone region, some big enough to topple skyscrapers for hundreds of miles around. Fortunately, there are no skyscrapers for hundreds of miles around.

Scientists discussed this topic at a geology conference in Denver in April. Here's my favorite paragraph from a Live Science article about the conference:

The [magma] reservoir is shaped like a dog's knobby chew toy, with one end
about 9 miles (15 km) below the center of Yellowstone National Park, and
the other rising to the northeast, about 3 miles (5 km) below the
surface.